formats/format_sln.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Anthony Minessale
   5  * Anthony Minessale (anthmct@yahoo.com)
   6  *
   7  * See http://www.asterisk.org for more information about
   8  * the Asterisk project. Please do not directly contact
   9  * any of the maintainers of this project for assistance;
  10  * the project provides a web site, mailing lists and IRC
  11  * channels for your use.
  12  *
  13  * This program is free software, distributed under the terms of
  14  * the GNU General Public License Version 2. See the LICENSE file
  15  * at the top of the source tree.
  16  */
  17
  18 /*! \file
  19  *
  20  * \brief RAW SLINEAR Format
  21  * \arg File name extensions: sln, raw
  22  * \ingroup formats
  23  */
  24
  25 #include "asterisk.h"
  26
  27 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  28
  29 #include "asterisk/mod_format.h"
  30 #include "asterisk/module.h"
  31 #include "asterisk/endian.h"
  32
  33 #define BUF_SIZE        320             /* 320 bytes, 160 samples */
  34 #define SLIN_SAMPLES    160
  35
  36 static struct ast_frame *slinear_read(struct ast_filestream *s, int *whennext)
  37 {
  38         int res;
  39         /* Send a frame from the file to the appropriate channel */
  40
  41         s->fr.frametype = AST_FRAME_VOICE;
  42         s->fr.subclass = AST_FORMAT_SLINEAR;
  43         s->fr.mallocd = 0;
  44         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
  45         if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
  46                 if (res)
  47                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
  48                 return NULL;
  49         }
  50         *whennext = s->fr.samples = res/2;
  51         s->fr.datalen = res;
  52         return &s->fr;
  53 }
  54
  55 static int slinear_write(struct ast_filestream *fs, struct ast_frame *f)
  56 {
  57         int res;
  58         if (f->frametype != AST_FRAME_VOICE) {
  59                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
  60                 return -1;
  61         }
  62         if (f->subclass != AST_FORMAT_SLINEAR) {
  63                 ast_log(LOG_WARNING, "Asked to write non-slinear frame (%d)!\n", f->subclass);
  64                 return -1;
  65         }
  66         if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
  67                         ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
  68                         return -1;
  69         }
  70         return 0;
  71 }
  72
  73 static int slinear_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
  74 {
  75         off_t offset=0,min,cur,max;
  76
  77         min = 0;
  78         sample_offset <<= 1;
  79         cur = ftello(fs->f);
  80         fseeko(fs->f, 0, SEEK_END);
  81         max = ftello(fs->f);
  82         if (whence == SEEK_SET)
  83                 offset = sample_offset;
  84         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
  85                 offset = sample_offset + cur;
  86         else if (whence == SEEK_END)
  87                 offset = max - sample_offset;
  88         if (whence != SEEK_FORCECUR) {
  89                 offset = (offset > max)?max:offset;
  90         }
  91         /* always protect against seeking past begining. */
  92         offset = (offset < min)?min:offset;
  93         return fseeko(fs->f, offset, SEEK_SET);
  94 }
  95
  96 static int slinear_trunc(struct ast_filestream *fs)
  97 {
  98         return ftruncate(fileno(fs->f), ftello(fs->f));
  99 }
 100
 101 static off_t slinear_tell(struct ast_filestream *fs)
 102 {
 103         return ftello(fs->f) / 2;
 104 }
 105
 106 static const struct ast_format slin_f = {
 107         .name = "sln",
 108         .exts = "sln|raw",
 109         .format = AST_FORMAT_SLINEAR,
 110         .write = slinear_write,
 111         .seek = slinear_seek,
 112         .trunc = slinear_trunc,
 113         .tell = slinear_tell,
 114         .read = slinear_read,
 115         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 116 };
 117
 118 static int load_module(void)
 119 {
 120         if (ast_format_register(&slin_f))
 121                 return AST_MODULE_LOAD_FAILURE;
 122         return AST_MODULE_LOAD_SUCCESS;
 123 }
 124
 125 static int unload_module(void)
 126 {
 127         return ast_format_unregister(slin_f.name);
 128 }
 129
 130 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw Signed Linear Audio support (SLN)");